Resumo:
Whole genome doubling is followed, over evolutionary time, by genome rearrangement through intra-and interchromosomal movement of genetic material. The genome halving problem is to reconstruct the ancestral genome on the basis of a decomposition of the present-day genome into a set of duplicated blocks of genes or DNA sequence dispersed among the chromosomes. A linear-time algorithm to find the ancestral genome that minimizes the genomic rearrangement distance to the present-day genome is available. Unfortunately this combinatorial optimization solution does not suffice as a solution to the evolutionary biology problem. The algorithmic result suffers from severe non-uniqueness; there may be large numbers of rather different solutions. Our goal is to counteract this problems by guiding the reconstruction by one or more reference, or outgroup, genomes. We illustrate with analyses of the genomes of cereals, yeasts and flowering plants.

In 1977, he was awarded the Prix Vincent of the Association canadienne-franÃ§aise pour l'avancement des sciences, and in 1995, he was named a Fellow of the Royal Society of Canada. In 2003, Dr. Sankoff was the recipient of the International Society for Computational Biology Senior Scientist Accomplishment Award, and in 2004 he received the Weldon Memorial Medal, which is presented annually by Oxford University to the person who has published the most noteworthy contribution to Biometric Science (the development of mathematical or statistical methods applied to problems in biology), regardless of nationality or university membership.

Dr. David Sankoff is a leader in applying mathematical approaches to the study of genes and genomes. His early work on sequence comparison, multiple alignment and RNA secondary structure is at the forefront of modern computational biology and bioinformatics. In recent years he has elaborated a program for the mathematical study of genome evolution and his ideas on the subject form the basis for much of the advanced work in the area.